Results of the Randomized Danish Lung Cancer Screening Trial with Focus on High-Risk Profiling

Genetic Variation in GSTP1, Lung Function, Risk of Lung Cancer, and Mortality

INTRODUCTION

Glutathione S-transferase pi 1 metabolizes carcinogens from tobacco smoke in the lung. We tested whether genetically altered glutathione S-transferase pi 1 activity affects lung function and risk for tobacco-related cancer and mortality in the general population.

METHODS

We genotyped 66,069 individuals from the white general population for two common functional variants in the glutathione S-transferase pi 1 gene (GSTP1)-amino acid isoleucine 105 changed to a valine (Ile105Val) and amino acid alanine 114 changed to a valine (Ala114Val)-and recorded lung function, lung cancer, tobacco-related cancer, and death as outcomes.

RESULTS

Lung function was increased stepwise with the Ile105Val genotype overall (p < 0.01) and among smokers separately (p < 0.01). Adjusted hazard ratios for lung cancer, tobacco-related cancer, and death were reduced stepwise with the Ile105Val genotype (p < 0.02): Ile105Val homozygotes and heterozygotes versus noncarriers had hazard ratios for lung cancer of 0.64 (0.47-0.89) and 0.93 (0.78-1.11), for tobacco-related cancer of 0.74 (0.60-0.92) and 0.92 (0.81-1.04), and hazard ratios for death of 0.87 (0.80-0.95) and 0.94 (0.89-0.99), respectively. Population prevented fractions of lung cancer, tobacco-related cancer, and death due to Ile105Val homozygosity were 4%, 3% and 2%, respectively. The Ala114Val genotype was associated with reduced mortality (p < 0.01) but not with lung function, lung cancer, or tobacco-related cancer.

CONCLUSION

GSTP1 Ile105Val was associated with increased lung function, reduced risk for lung cancer and tobacco-related cancer, and reduced all-cause mortality in the general population.

Lung Cancer Screening

Lung cancer is the leading cause of cancer death in the United States. More than 80% of these deaths are attributed to tobacco use, and primary prevention can effectively reduce the cancer burden. The National Lung Screening Trial showed that low-dose computed tomography (LDCT) screening could reduce lung cancer mortality in high-risk patients by 20% compared with chest radiography. The US Preventive Services Task Force recommends annual LDCT screening for persons aged 55 to 80 years with a 30-pack-year smoking history, either currently smoking or having quit within 15 years.

AJRCCM: 100-Year Anniversary. The Shifting Landscape for Lung Cancer: Past, Present, and Future

The past century has witnessed a transformative shift in lung cancer from a rare reportable disease to the leading cause of cancer death among men and women worldwide. This historic shift reflects the increase in tobacco consumption worldwide, spurring public health efforts over the past several decades directed at tobacco cessation and control. Although most lung cancers are still diagnosed at a late stage, there have been significant advances in screening high-risk smokers, diagnostic modalities, and chemopreventive approaches. Improvements in surgery and radiation are advancing our ability to manage early-stage disease, particularly among patients considered unfit for traditional open resection. Arguably, the most dramatic progress has occurred on the therapeutic side, with the development of targeted and immune-based therapy over the past decade. This article reviews the major shifts in the lung cancer landscape over the past 100 years. Although many ongoing clinical challenges remain, this review will also highlight emerging molecular and imaging-based approaches that represent opportunities to transform the prevention, early detection, and treatment of lung cancer in the years ahead.

Risk stratification based on screening history: the NELSON lung cancer screening study

BACKGROUND

Debate about the optimal lung cancer screening strategy is ongoing. In this study, previous screening history of the Dutch-Belgian Lung Cancer Screening trial (NELSON) is investigated on if it predicts the screening outcome (test result and lung cancer risk) of the final screening round.

METHODS

15 792 participants were randomised (1:1) of which 7900 randomised into a screening group. CT screening took place at baseline, and after 1, 2 and 2.5 years. Initially, three screening outcomes were possible: negative, indeterminate or positive scan result. Probability for screening outcome in the fourth round was calculated for subgroups of participants.

RESULTS

Based on results of the first three rounds, three subgroups were identified: (1) those with exclusively negative results (n=3856; 73.0%); (2) those with ≥1 indeterminate result, but never a positive result (n=1342; 25.5%); and (3) with ≥1 positive result (n=81; 1.5%). Group 1 had the highest probability for having a negative scan result in round 4 (97.2% vs 94.8% and 90.1%, respectively, p<0.001), and the lowest risk for detecting lung cancer in round 4 (0.6% vs 1.6%, p=0.001). 'Smoked pack-years' and 'screening history' significantly predicted the fourth round test result. The third round results implied that the risk for detecting lung cancer (after an interval of 2.5 years) was 0.6% for those with negative results compared with 3.7% of those with indeterminate results.

CONCLUSIONS

Previous CT lung cancer screening results provides an opportunity for further risk stratifications of those who undergo lung cancer screening.

TRIAL REGISTRATION NUMBER

Results, ISRCTN63545820.

Malignancy risk estimation of screen-detected nodules at baseline CT: comparison of the PanCan model, Lung-RADS and NCCN guidelines

Objectives

To compare the PanCan model, Lung-RADS and the 1.2016 National Comprehensive Cancer Network (NCCN) guidelines for discriminating malignant from benign pulmonary nodules on baseline screening CT scans and the impact diameter measurement methods have on performances.

Methods

From the Danish Lung Cancer Screening Trial database, 64 CTs with malignant nodules and 549 baseline CTs with benign nodules were included. Performance of the systems was evaluated applying the system's original diameter definitions: D^longest-C (PanCan), D^meanAxial (NCCN), both obtained from axial sections, and D^mean3D (Lung-RADS). Subsequently all diameter definitions were applied uniformly to all systems. Areas under the ROC curves (AUC) were used to evaluate risk discrimination.

Results

PanCan performed superiorly to Lung-RADS and NCCN (AUC 0.874 vs. 0.813, p = 0.003; 0.874 vs. 0.836, p = 0.010), using the original diameter specifications. When uniformly applying D^longest-C, D^mean3D and D^meanAxial, PanCan remained superior to Lung-RADS (p < 0.001 – p = 0.001) and NCCN (p < 0.001 – p = 0.016). Diameter definition significantly influenced NCCN’s performance with D^longest-C being the worst (D^longest-C vs. D^mean3D, p = 0.005; D^longest-C vs. D^meanAxial, p = 0.016).

Conclusions

Without follow-up information, the PanCan model performs significantly superiorly to Lung-RADS and the 1.2016 NCCN guidelines for discriminating benign from malignant nodules. The NCCN guidelines are most sensitive to nodule size definition.

Key Points

• PanCan model outperforms Lung-RADS and 1.2016 NCCN guidelines in identifying malignant pulmonary nodules.

• Nodule size definition had no significant impact on Lung-RADS and PanCan model.

• 1.2016 NCCN guidelines were significantly superior when using mean diameter to longest diameter.

• Longest diameter achieved lowest performance for all models.

• Mean diameter performed equivalently when derived from axial sections and from volumetry.

Recommendations from the European Society of Thoracic Surgeons (ESTS) regarding computed tomography screening for lung cancer in Europe

In order to provide recommendations regarding implementation of computed tomography (CT) screening in Europe the ESTS established a working group with eight experts in the field. On a background of the current situation regarding CT screening in Europe and the available evidence, ten recommendations have been prepared that cover the essential aspects to be taken into account when considering implementation of CT screening in Europe. These issues are: (i) Implementation of CT screening in Europe, (ii) Participation of thoracic surgeons in CT screening programs, (iii) Training and clinical profile for surgeons participating in screening programs, (iv) the use of minimally invasive thoracic surgery and other relevant surgical issues and (v) Associated elements of CT screening programs (i.e. smoking cessation programs, radiological interpretation, nodule evaluation algorithms and pathology reports). Thoracic Surgeons will play a key role in this process and therefore the ESTS is committed to providing guidance and facilitating this process for the benefit of patients and surgeons.

Pilot study on use of home telephoning to identify and recruit high-risk individuals for lung cancer screening

Widespread lung cancer screening with low-dose computed tomography is urgently needed in Europe to identify lung cancers early and reduce lung cancer deaths. The most effective method of identifying high-risk individuals and recruiting them for screening has not been determined. In the present pilot study we investigated direct telephoning to families as a way of identifying high risk individuals and recruiting them to a screening/smoking cessation program, that avoided the selection bias of voluntary screening. Families in the province of Milan, Italy, were contacted by telephone at their homes and asked about family members over 50 years who were heavy smokers (30 or more pack-years). Persons meeting these criteria were contacted and asked to participate in the program. Those who agreed were given an appointment to undergo screening and receive smoking cessation counseling. Among the 1000 contacted families, involving 2300 persons, 44 (1.9%) were eligible for LDCT screening, and 12 (27%) of these participated in the program. The cost of this recruitment strategy pilot study was around 150 euro per screened subject. We obtained useful information on the proportion of the general population eligible for lung cancer screening and the proportion of those who responded. However the cost of home telephone calling is probably too high to be practicable as a method of recruiting high risk persons for screening. Alternative recruitment methods, possibly involving family physicians practitioners, need to be investigated.

Medical follow-up of workers exposed to lung carcinogens: French evidence-based and pragmatic recommendations

Background

The aim of this work was to establish recommendations for the medical follow-up of workers currently or previously exposed to lung carcinogens.

Methods

A critical synthesis of the literature was conducted. Occupational lung carcinogenic substances were listed and classified according to their level of lung cancer risk. A targeted screening protocol was defined.

Results

A clinical trial, National Lung Screnning Trial (NLST), showed the efficacy of chest CAT scan (CT) screening for populations of smokers aged 55–74 years with over 30 pack-years of exposure who had stopped smoking for less than 15 years. To propose screening in accordance with NLST criteria, and to account for occupational risk factors, screening among smokers and former smokers needs to consider the types of occupational exposure for which the risk level is at least equivalent to the risk of the subjects included in the NLST. The working group proposes an algorithm that estimates the relative risk of each occupational lung carcinogen, taking into account exposure to tobacco, based on available data from the literature.

Conclusion

Given the lack of data on bronchopulmonary cancer (BPC) screening in occupationally exposed workers, the working group proposed implementing a screening experiment for bronchopulmonary cancer in subjects occupationally exposed or having been occupationally exposed to lung carcinogens who are confirmed as having high risk factors for BPC. A specific algorithm is proposed to determine the level of risk of BPC, taking into account the different occupational lung carcinogens and tobacco smoking at the individual level.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4114-1) contains supplementary material, which is available to authorized users.

Lung cancer screening with low-dose CT in Europe: strength and weakness of diverse independent screening trials

A North American trial reported a significant reduction of lung cancer mortality and overall mortality as a result of annual screening using low-dose computed tomography (LDCT). European trials prospectively tested a variety of possible screening strategies. The main topics of current discussion regarding the optimal screening strategy are pre-test selection of the high-risk population, interval length of LDCT rounds, definition of positive finding, and post-test apportioning of lung cancer risk based on LDCT findings. Despite the current lack of statistical evidence regarding mortality reduction, the European independent diverse strategies offer a multi-perspective view on screening complexity, with remarkable indications for improvements in cost-effectiveness and harm-benefit balance. The UKLS trial reported the advantage of a comprehensive and simple risk model for selection of patients with 5% risk of lung cancer in 5 years. Subjective risk prediction by biological sampling is under investigation. The MILD trial reported equal efficiency for biennial and annual screening rounds, with a significant reduction in the total number of LDCT examinations. The NELSON trial introduced volumetric quantification of nodules at baseline and volume-doubling time (VDT) for assessment of progression. Post-test risk refinement based on LDCT findings (qualitative or quantitative) is under investigation. Smoking cessation remains the most appropriate strategy for mortality reduction, and it must therefore remain an integral component of any lung cancer screening programme.

What factors do patients consider most important in making lung cancer screening decisions? Findings from a demonstration project conducted in the Veterans Health Administration

INTRODUCTION

The National Lung Screening Trial recently reported that annual low-dose computed tomography screening is associated with decreased lung cancer mortality in high-risk smokers. This study sought to identify the factors patients consider important in making lung cancer screening (LCS) decisions, and explore variations by patient characteristics and LCS participation.

MATERIAL AND METHODS

This observational survey study evaluated the Minneapolis VA LCS Clinical Demonstration Project in which LCS-eligible Veterans (N=1388) were randomized to either Direct LCS Invitation (mailed with decision aid, N=926) or Usual Care (provider referral, N=462). We surveyed participants three months post-randomization (response rate 44%) and report the proportion of respondents rating eight decision-making factors (benefits, harms, and neutral factors) as important by condition, patient characteristics, and LCS completion.

RESULTS

Overall, the most important factor was personal risk of lung cancer and the least important factor was health risks from LCS. The reported importance varied by patient characteristics, including smoking status, health status, and education level. Overall, the potential harms of LCS were reported less important than the benefits or the neutral decision-making factors. Exposure to Direct LCS Invitation (with decision aid) increased Veterans' attention to specific decision-making factors; compared to Usual Care respondents, a larger proportion of Direct LCS Invitation respondents rated the chance of false-positive results, LCS knowledge, LCS convenience, and anxiety as important. Those completing LCS considered screening harms less important, with the exception of incidental findings.

CONCLUSION

Decision tools influence Veterans' perceptions about LCS decision-making factors. As the factors important to LCS decision making vary by patient characteristics, targeted materials for specific subgroups may be warranted. Attention should be paid to how LCS incidental findings are communicated.

Coping with stigma: the experiences of Chinese patients living with lung cancer

PURPOSE/OBJECTIVES

To describe the experiences of stigma and coping strategies among patients with lung cancer in China.

RESEARCH APPROACH

Qualitative.

SETTING

The oncology department at Liaocheng Peoples Hospital.

PARTICIPANTS

A purposive sample of 17 patients experiencing stigma related to lung cancer voluntarily participated in data collection.

METHODOLOGIC APPROACH

Individual, semistructured qualitative interviews were chosen. Participants completed about a 30-min focused interview. Exploratory qualitative approach guided data analysis.

FINDINGS

Three main thematic elements emerged from the interview data:(1) sources of stigma, such as smoking, decreased ability to work, difficulties caring for self and family, damage to self-image, and cough and expectoration; (2) experiences of stigma, including feelings of stigma, remorse, loss of dignity, uselessness, social isolation, perceived exclusion, rejection, and discrimination; and (3) coping strategies, such as concealing the fact of sickness, reducing social activities, seeking medical assistance, adhering to treatment, and disclosing dissatisfaction.

CONCLUSIONS

Our results indicate the presence of perceived stigma among patients with lung cancer. Future work should address the stigma associated with lung cancer and its related factors.

INTERPRETATION

As point-of-care providers, staff nurses are well positioned to develop effective interventions to help patients deal with stigma and to accomplish the goal of providing holistic nursing care.

Low-dose computed tomography screening for lung cancer in populations highly exposed to tobacco: A systematic methodological appraisal of published randomised controlled trials

Low-dose computed tomography (LDCT) screening recommendations for lung cancer are contradictory. The French National Authority for Health commissioned experts to carry a systematic review on the effectiveness, acceptability and safety of lung cancer screening with LDCT in subjects highly exposed to tobacco. We used MEDLINE and Embase databases (2003-2014) and identified 83 publications representing ten randomised control trials. Control arms and methodology varied considerably, precluding a full comparison and questioning reproducibility of the findings. From five trials reporting mortality results, only the National Lung Screening Trial found a significant decrease of disease-specific and all-cause mortality with LDCT screening compared to chest X-ray screening. None of the studies provided all information needed to document the risk-benefit balance. The lack of statistical power and the methodological heterogeneity of European trials question on the possibility of obtaining valid results separately or by pooling. We conclude, in regard to the lack of strong scientific evidence, that LDCT screening should not be recommended in subjects highly exposed to tobacco.

Lung cancer screening in patients with chronic obstructive pulmonary disease

Lung cancer and chronic obstructive pulmonary disease (COPD) are two intimately related diseases, with great impact on public health. Annual screening using low-dose computed tomography (LDCT) of the chest significantly reduces mortality due to lung cancer, and several scientific societies now recommend this technique. COPD, defined by the presence of airflow obstruction [forced expiratory volume and forced vital capacity (FVC) ratio less than 0.70], and their clinical phenotypes, namely emphysema and chronic bronchitis, have been associated with increased lung cancer risk. Several epidemiological studies, including lung cancer screening trials, have found a 2- to 4-fold increase in lung cancer risk in patients with COPD when compared to individuals without airflow obstruction. Part of the risk attributed to airflow obstruction appears to be derived from the presence of radiographic emphysema. The latter has proven to be an important lung cancer risk factor in smokers without airflow obstruction and even in never smokers. This evidence supports the idea of including patients with COPD and/or emphysema in lung cancer screening programs. There is evidence that lung cancer screening in this population is effective and can potentially reduce mortality. Specific lung cancer risk scores have been developed for patients with COPD [COPD lung cancer screening score (LUCSS) and COPD-LUCSS-diffusing capacity for carbon monoxide (DLCO)] to identify those at high risk. A multidisciplinary approach for an adequate patient selection, especially of patients with severe disease, is key to maximize benefits and reduce harms from lung cancer screening in this population. Patients with COPD included in lung cancer screening programs could also benefit from other interventions, such as smoking cessation and adequate treatment.

Early detection of lung cancer

Most patients with lung cancer are diagnosed when they present with symptoms, they have advanced stage disease, and curative treatment is no longer an option. An effective screening test has long been desired for early detection with the goal of reducing mortality from lung cancer. Sputum cytology, chest radiography, and computed tomography (CT) scan have been studied as potential screening tests. The National Lung Screening Trial (NLST) demonstrated a 20% reduction in mortality with low-dose CT (LDCT) screening, and guidelines now endorse annual LDCT for those at high risk. Implementation of screening is underway with the desire that the benefits be seen in clinical practice outside of a research study format. Concerns include management of false positives, cost, incidental findings, radiation exposure, and overdiagnosis. Studies continue to evaluate LDCT screening and use of biomarkers in risk assessment and diagnosis in attempt to further improve outcomes for patients with lung cancer.